Attenuator failure mode?

[robert1111]

If a low powered (example 1 watt) SMA coaxial attenuator is subjected to power levels exceeding its rating (example subjected to 5 watts continuous), what is the mode of failure?  Does it fail "open" or "short"?  Thank you.

[dl6lr]

I would expect open. All attenuators that I measured failed with high impedance after overload. Additonally they are also sensitive to static discharge.

[Joel_Dunsmore]

Yup, in general they are Pi type structures (shunt R, series R, shunt R) although higher frequency ones look more like a patch of resist material with ground on the side and contacts on the ends. Most over power tends to heat the resist and raise it's ohms per square, until it becomes quite high. It can sometimes overpower so much it sputters off the material to a full open. I've never seen on fail by shorting.

[rfclown]

Nice to see you on the forum Dr. Joel. You helped my years ago (on some other forum) in fixing an 8753 of mine.